The history of the Shelby Mustang program from 1965 to 1970 is the story of a collaboration that started with genuine purpose and ended with branding.

The 1965 and 1966 GT350s were genuinely modified cars — purpose-built competition vehicles that could be registered for the street. The 1967 and 1968 cars were more refined and better equipped but less focused in their purpose.

By 1969 and 1970, the Shelby cars were primarily visual upgrades to the Mustang, ordered through Ford dealers and assembled with cosmetic modifications that Shelby's organization oversaw. The performance credentials of the early cars had been diffused into a premium brand.

This trajectory doesn't diminish the later cars — they're beautiful and competent. It just explains why the 1965 GT350 commands a premium that the 1969 GT500 doesn't match.